Gallagher, William

Lynch, Seodhna M

McKenna, Declan J

McKenna, Michael

O'Neill, Karla

Walsh, CP

watson, william

English

Ulster University's Research Portal

Poster No: 100 Translational INVESTIGATION OF MIR-205 EXPRESSION AND ITS METHYLATION STATUS IN PROSTATE CANCER  SM Lynch1, KM O'Neill2, MM McKenna3, CP Walsh4, W Watson5, WM Gallagher1, DJ McKenna4 1Cancer Biology and Therapeutics Laboratory, UCD Conway Institute, University College Dublin, Dublin, Ireland 2Centre for Experimental Medicine, Queen's University Belfast, Belfast, N. Ireland 3Department of Cellular Pathology, Western Health & Social Care Trust, Altnagelvin Area Hospital, Derry, N. Ireland 4Biomedical Sciences Research Institute, Ulster University, Coleraine, N. Ireland 5UCD School of Medicine, UCD Conway Institute, University College Dublin, Dublin, Ireland In prostate cancer (PCa), abnormal expression of several microRNAs (miRNAs) has been reported. Increasing evidence shows that aberrant epigenetic regulation of miRNAs is a contributing factor to their altered expression in cancer. In this study, we investigated whether expression of miR-205 in PCa is related to the DNA methylation status of its promoter and locus region. PCR analysis of miR-205 expression was performed in PCa cell-lines and clinical specimens. CpG methylation analysis of the miR-205 promoter and miR-205 locus was performed in PCa cell-lines and clinical specimens via pyrosequencing. The effect on promoter and locus methylation status in cells treated with demethylating agents including 5-aza-2’deoxycytidine (decitabine), knockdown of DNA methyltransferase 1 (DNMT1) and knockdown of enhancer of zeste homolog 2 (EZH2) was also examined. Finally, the biological significance of miR-205 in PCa cells was assessed using in vitro bioassays. miR-205 was significantly down-regulated across PCa cell-lines. This correlated inversely with the methylation status of the miR-205 promoter and miR-205 locus, which is hypermethylated across this panel of cell-lines in both regions. Interestingly, a trend towards an inverse correlation was evident between miR-205 methylation, for both regions, and miR-205 expression levels in clinical specimens. Moreover, in PC3 cells, miR-205 expression was subsequently elevated by treatment with demethylating agents suggesting its expression is regulated by methylation. miR-205 promoter and locus methylation status, following treatment with 5-aza-2 deoxycytidine in PC3 cells, showed no change in methylation levels in either region. Finally, over-expression of miR-205 in PC3 cells inhibited growth and clonogenic potential, as well as inducing apoptosis.  Preliminary findings provide evidence that miR-205 is abnormally expressed in PCa and appears to have a tumour suppressor role in PCa. This study investigated the role of DNA methylation in regulating miR-205 expression. It is evident that DNA methylation of the regions analysed may not be responsible for regulating miR-205 expression; thus, other regions within the promoter and locus regions, which have not been identified, may be more important. Furthermore, histone modifications may have a role, alongside DNA methylation, in regulating miR-205 expression. Future work entails investigating the biological and prognostic value of miR-205 in PCa.   

INVESTIGATION OF MIR-205 EXPRESSION AND ITS METHYLATION STATUS IN PROSTATE CANCER

https://pure.ulster.ac.uk/ws/files/76986168/Lynch_et_al_investigation_of_mir_205_expression_and_its_methylation_status_in_prostate_cancer.pdf

INVESTIGATION OF MIR-205 EXPRESSION AND ITS METHYLATION STATUS IN PROSTATE CANCER

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